Introduction: Building the Overkill Control Box, by Ian Hillway
I designed the Overkill Control Box to meet a specific need, to be able to control a spaceship in a video game with the ability to move forward, back, left and right, up, and down, plus a whole lot of buttons to control different functions on the ship.
It started out very simple, but evolved into something much more robust than I expected.
If you want to see the evolution of the Overkill Control Box, watch the attached video. Otherwise, feel free to skip ahead.
Step 1: Tools You Will Need
To complete this project you will need to 3D print and solder. If you don't know how, find a friend that does and can help you or do that part for you. You can order the Teensy 3.6 with the pins already in it, but there are a few steps where you can't go any further if you can't solder, so consider these skills in advance.
You will need a soldering iron for this and a solder sucker or solder wick. You will also need some needle nose pliers, wire cutters (or you can use the ones built into your pliers if you need to), a wire stripper or some other way to cut the insulation off of wire (a razor will work in a pinch), a little bit of electrical tape, and a razor/exacto knife.
Step 2: Download the Files
Download the zip file for the Overkill Control Box. The zip file contains all the .stl files needed to 3D print the Overkill Control Box along with the teensyduino code necessary to program the Teensy 3.6 that serves as its brain.
There are two different versions of the body of the Overkill Control Box. When I started, I had the wrist in a lower position. After using the box for a while I redesigned the box to hold the wrist in a higher position so it pushes the hand forward and extends the reach of the fingers, making it easier to reach the keys in the back row. My hands are about 18 cm, or just under 7 inches from the base of my palm to the tip of my longest finger. Unless your hands are noticeably larger than this, I recommend using the "OCB_BodyHigh.stl" file and discarding the "OCB_BodyLow.stl" file.
Attachments
Step 3: 3D Print the Parts
I printed all the parts on low quality (0.4 mm) except the body, which I printed in high quality (0.1 mm). A few of the parts are already set up to print upside down so that the smoother part of the print will be facing up when you are done --or to avoid overhangs-- so you shouldn't have to flip any parts for printing. Your software may try to place them out of the print area, so you may have to center them on the print bed when you print.
All parts are designed to be printable without supports.
If you don't have any experience 3D printing, ask your friends, ask your schoolmates, ask your teachers, or look for a makerspace nearby and ask whoever you can. If you can't find access to a 3D printer, there are services out there that can 3D print files for you, but I haven't used them so I can't vouch for their quality.
Once you are done, you should have all the parts shown in the photo.
As mentioned previously, unless you believe that your hands are long enough to need it, i recommend discarding the "BodyLow" file.
Step 4: Order the Electronics
In addition to the 3D printed parts, you will need a variety of electronic components. I was able to order most parts online from Amazon. Here is what you are going to need. All prices are in US dollars at the time I wrote this, based on a quick internet search. You may be able to get better prices by shopping around or ordering from specific sellers or buying from a local electronics shop.
1 Teensy 3.6 ($36) or ($45) with pins. Order it with pins unless you want to solder them yourself in which case you will need 48 "male pin headers." For this project you don't need headers on all the holes, just the two outside rows.
1 USB 2.0 A Male to Micro B 5-pin Male cable. ($4) Many people have one of these lying around already so you probably already have this. This will be what you use to connect the control box to the computer, so make sure that you get a length that will work with your setup.
5 "male pin headers" to replace the pins on the mini joystick so they point the way we need them to.
1 PSP 1000 Analog Joystick ($8)
23 keyboard keyswitches. ($40) or ($10) These come from a variety of manufacturers and in a variety of different colors, which correspond to different characteristics. I ordered mine for less than $10 for 40 by shopping around and ordering from a re-seller. Online keyswitch re-sellers often run out of popular switches, so if the site you are looking at doesn't have what you need, check a few other sites and you should be able to find what you are looking for. It doesn't matter if you get the plate mount type or the PCB mount type for our purposes, but the plate mount may give you a little extra room when you are soldering, so if you need to choose between different ones, you can use that as a tiebreaker and go for plate mount type.
23 Keycaps ($0) to ($40+). If you search online you can find 3D models to print your own keycaps on thingiverse or other websites at no additional cost. You will need a total of 23 keycaps for the box. I was able to find two 12-key number row plus "-" and "+" key sets on clearance from an online store that gave me 24 keys for $15. Some places sell novelty keycaps for as much as $5 each, so this could get really expensive if you let it. If you have an old mechanical keyboard, or find one at a thrift store, you can cannibalize the keycaps if it is the right kind of keyboard. You will know because the right kind have a + shaped hole in the back if you pull them off and turn them over. I recommend that you print them yourself if you can't find a deal.
6 "uxcell 4 pin tactile momentary 12mm x 12mm x 8mm switch with cap" ($5 for 10) If you want to substitute for a different cap or button style, it should still work as long as the base is the same size and shape, with the same pin placement. There are some that have round buttons. The square button caps often sit a little crooked since they wiggle, so if you are bothered by that, you may want to give the round caps or cap-less ones a try. Just be sure to look at the height before you order. I wouldn't recommend anything less than 8 mm, but you might be able to go up to 12 mm and still be comfortable.
1 "10x10x9mm 6 Pin 5 Way Momentary Square SMD SMT Tactile Switch" ($9 for 5)
1 "FICBOX Dual-axis XY Joystick" ($9 for 5) Other brands might work just fine, but I designed this around this brand, if the alignment or size of the board you get is different they may not fit properly.
3 feet of 22 gauge solid hook up wire. ($10 for 100ft) Shop around or visit a local hobby store, you don't need nearly that much.
38 male to female jumper wires 20 cm length. ($7 per 120) These often come as "ribbons," that's just fine, and you can peel them apart as necessary.
6 female to female jumper wires 20 cm length ($0 - included in the above set of 120 if you buy a variety pack)
Step 5: Program the Teensy 3.6
You will need to download the Arduino IDE, which is the program that lets you program Arduino-based microcontrollers. You can get it here: https://www.arduino.cc/en/Guide/HomePage
Once you have that installed, you need the Teensyduino add on that contains the additional software needed to program the Teensy series of microcontrolers. You can get it here: https://www.pjrc.com/teensy/teensyduino.html
Once you have it all installed, sonnect the Teensy 3.6 to your computer with the USB cable, open the file "Overkill_Control_Box_Teensyduino_Code.ino" that is in the zip file you downloaded earlier, and click on the arrow pointing to the right (see the attached picture) to upload the code to your Teensy 3.6. You will probably need to press the reset button on the Teensy board to upload the code, don't worry, it will show you a picture of where that is if you do.
If you want to reprogram your Teensy once the board is all put together, there is a small hole on the left side of the box. If you straighten a paperclip and reach through the hole, there is another hole inside the part that holds the Teensy board in place. You may have to feel around a little to get the paperclip lined up just right, but if you go in straight, you should find it without too much trouble. This will let you press the button with the paperclip even after you have finished assembly.
I am not an expert at coding, so if you want to innovate or improve it and share your code, please do! I put comments in the code so it should be pretty clear what all the parts do if you want to make changes.
One of the things that gave me some trouble was that the PSP 1000 joystick slider has a big dead zone and doesn't have consistent max and min values for each axis. To solve this problem, the code calculates those as you use it. If you find that the PSP 1000 joystick is experiencing drift, move it in a big circle and it should calibrate for you and the problem should go away.
Step 6: Practice Fitting All the Parts Together
I put together a video walk-through of how all of the parts fit together. Before you go any further, practice putting all the parts together so that you know how things are going to fit. It is much easier to make changes, sand edges, or make other adjustments now, before any electronics are involved.
During this step you will also insert the keyswitches and the PSPSlideMount into the KeyswitchPlate; follow the instructions in the video.
Once you are done, take the box apart again but leave they keys and the PSPSlideMount in place in the KeyswitchPlate.
Step 7: Solder the KeyswitchPlate Ground Wire
Once all the keys are inserted into the KeyswitchPlate, turn it over so that you can see the underside where all the pins are. For these switches, the direction of electrical flow isn't important, so don't worry about that.
Look at your keyswitches and notice how the two pins are just a little different. For mine they are in slightly different positions and one is copper plated. This only matters for consistency, it is more orderly and easier to keep track of if you do all the switches the same way.
Pull out the 22 gauge solid hook up wire and choose a key in one of the corners, I chose the top right. strip about 3 mm off the end and solder it to the pin you chose. In the case of my switches, I used all the copper plated pins for this step. Always solder in a well ventilated area, preferably with a fan and carbon filter to suck away the fumes. Inhaling solder smoke isn't healthy.
In the first version of this project, I soldered individual small wires between each pin in the chain. This caused a lot of technical difficulty and I recommend just melting a bit of the insulation away to expose the wire inside and soldering that to the next pin without cutting the wire.
Bend the wire so that it has a gentle curve between the pins and melt away the insulation at the point where it would touch the pin on the next keyswitch. Don't be timid with this, you can't melt the wire and it's ok if you melt away a little too much. If you don't leave a little curve in the wire and you go from one pin to the next with a straight wire, it should be ok, but I consider it good practice to make sure that your wires always have a little bit of slack; it allows things to flex if necessary and adds some give if the wire expands or contracts with temperature changes.
Once you have the wire soldered between the first and second keyswitches, repeat the process across the row, down, then across the next row and so on until you get to the end. Remember to route the wire around the hole where the PSP slider goes; it has wires of its own so you want to give them room. When you have finished soldering to the last keyswitch, measure about 3 cm or 1 inch of extra wire to hang off the end and then strip about 1 cm of insulation off the end as shown in the last picture with this step.
Before you consider this step done, grab the wire next to each solder point with your pliers and try and wiggle the wire gently. If the wire moves, your solder isn't connected to that switch; remelt the solder at that point and and add a little more solder to the pin until everything feels solid. Every time I have had problems with a key not working once I have everything all put together, it comes back to a loose connection here, so take the time to check them all and save yourself a headache later.
Step 8: Solder the Wires on the PSP 1000 Joystick
Take the PSP 1000 joystick and cut off the two mounting tabs on the corners so that all four corners match. (see the second photo)
Cut four sections of 22 gauge solid hook up wire that are about 4 cm or 1.5 inch long and strip about 3 mm of insulation off of one end and 1 cm off the other end of each. Bend the ends that have less exposed wire at the tip 90 degrees as shown in photo 3.
See photo 4, ideally the insulation ends right around the point where it starts sticking out past the board. It is better to make them too long than too short. If they are too long you can always just bend them out of the way later.
Notice in the last picture, I soldered mine with the bent part pointing in so that the wires are all very close to the edge of the switch. This will actually give you less room to work with based on where the hole in the mounting plate is. I recommend soldering the wires on with the bent part facing out toward the edge of the board, so the wires are sticking up a bit further from the edge. Either way will work, one just gives you a little more room for error.
Step 9: Prep the Male to Female Jumper Wires
Jumper wires often come in a ribbon configuration that makes them easier to handle during manufacturing and distribution, to get a single wire just start at one end and peel one wire off of the ribbon.
We aren't going to actually use the male pin on the wire. Using the tip of an exacto knife, a toothpick, or something else with a slender point, find the small tab on the black plastic box just behind the male pin and pry the tab up a little. This will let you slide the plastic box off of the end revealing just the metal and wire.
Don't modify the female ends of the wire, we will be using them as is. Only remove the plastic box from the male end.
Once the plastic box is removed, you will see that the tip has three main parts, the place where it is crimped on to the wire, a small box shaped area, and the tip. We want to cut between the tip and the box, so that the box is the new end of the wire. Be sure to look at all the pictures and be sure you are cutting in the right place.
Once the male ends are off, you can peel apart the individual wires so they are ready to use. (If you do this at an earlier step or have unattached wires, that's fine, they are just a little easier to handle as a ribbon without getting tangled when doing some of the prep work.)
Step 10: Solder Jumper Wires to the Keyswitches
Since we trimmed the male end of the wire, there is now a hollow metal box at the end. Put that right over the pin of the first keyswitch so it fits inside. Solder the jumper wire to the pin, your goal is to push in enough solder that it fills that little box at the end of the jumper wire with solder.
Once you have done the first keyswitch, repeat for the rest of the keyswitches.
Step 11: Place the PSP 100 Joystick
Line up the PSP 1000 joystick so that the wires you soldered drop through the hole and it fits snugly in the PSPSlideMount. Check the underside to make sure that you are happy with the length of the wires before continuing.
To keep the PSP 1000 joystick in place you can use some double sided tape underneath it, or you can use glue. I don't recommend superglue, since I have had problems with it warping PLA in the past. White glue, wood glue,. or hot glue should work well.
If you use hot glue, just put a little bit at each of the corners. Your keycaps are going to be very close to the edges of the PSP 1000 joystick and any little bit of hot glue on the sides will get them stuck. If you find that your keys are sticking because of this you will need to trim away any excess hot glue. Just a tiny bit in the corners should do the trick.
Step 12: Practice Fitting the MiniPanel Together
Before we solder any of the parts for the minipanel, fit all the parts together and make sure that you know how everything fits. The minipanel has several buttons that are very close together and has the tightest tolerances for this whole project.
The minipanel has three parts, the first is the plate that holds all the buttons.They need to be inserted very straight in order to fit. Use the picture as a guide to fit all of the buttons in place.
The next piece fits over the top with the smooth side up and holds the tops of all the switches in place. When putting the switches in the bottom panel you could put the switches in one at a time, now that they are all in place, this piece will need to go on just right. Spend some time with this piece, moving around and pressing on different spots firmly. You will need to be patient and firm, and once it pops fully in place you shouldn't see any gaps around the edge. If you see gaps, you may be tempted to use glue, but be patient, once you get it right you will feel it pop into place and it will stay firmly together.
The third part is completely open in the middle, it has four pins that fit into holes in the underside of the MiniPanel and adds thickness.
Once you have it all together, take it apart again. Don't worry, it is easier the second time.
Step 13: Prep the Uxcell Switches
The uxcell switches that I bought have removable caps. Take the caps off first for easy handling while you are working.
Each switch has four pins, two on each side. The way these work is that the electricity flows through the switch through the pins that are right next to each other, not across to the far side. This means that we can remove the pins on one side and it won't harm the switch. For our design, we need to do this.
It doesn't matter which side you remove the pins from, as long as you remove the two that are right next to each other. If you bend the pin up, then back down once or twice it will snap off cleanly. When you are done, you should have two pins left that are next to each other, like in the picture.
Then, using one of the male to female wires we prepared earlier, solder the trimmed male end to one of the pins and leave the other unsoldered. Like before, our goal is to put the pin inside the box at the end of the wire, then fill it up with solder so it holds firmly.
Step 14: Solder the 5-way Switch
Your 5-way switch has a forward and a back. Notice in the picture that the top two tabs sticking off of the sides are a little closer to each other than the third tab. The ones closer together are "up" or forward.
Cut one section of 22 gauge solid hook up wire that is about 4 cm or 1.5 inch long and strip about 3 mm of insulation off of one end and 1 cm off the other end of each. Bend the end with less exposed wire at the tip 90 degrees. This should be just the same as the wires we prepared for the PSP 1000 Joystick.
Turning the 5-way switch over so you can see the bottom and the two closer tabs on each side are pointing up, the top right tab is the ground for this switch. Solder the section of 22 gauge solid hook up wire to the underside of this tab so that when the switch is right side up, the wire will point straight down.
Solder the trimmed male end of a jumper wire to the underside of each of the remaining tabs in the same way, so that when upright it will point straight down.
Step 15: Assemble the MiniPanel
This is where practicing putting the minipanel together will come in handy. Feed the ends of the wires down through the holes as you put each switch into place.
When you install the 5-way switch, remember to note which way is "up" and make sure it points to the center of the minipanel and it isn't at pointing to the edge of the minipanel. If when you look from the underside, your section of 22 gauge solid hook up wire is near the middle of the minipanel, you did it right.
Snap all three parts of the minpanel together to complete the part.
Step 16: Solder the MiniPanel Ground Wire
Remember how we created a chained wire for the keyswitches to serve as a ground for all of them? We want to do the same thing here to connect the one unsoldered pin on each switch. At the end, solder it to the ground wire from the 5 way switch. Be sure to leave one end sticking out with about 1 cm of the inner wire exposed, we will need this to hook it to the ground later.
This is a tricky step. and requires soldering in tight spaces. If you prefer, you can solder a ground wire onto each of the switches like you did for the 5-way switch before you assemble all the parts together, and then chain all of those together afterward. It will make your wires stick out further, but you should have plenty of room and may be easier for beginners.
Look at the wires attached to the 5-way switch. They are pretty close to each other. To prevent anything from touching something it shouldn't, wrap a little electrical tape around any metal parts that are close to other metal parts to insulate them.
Step 17: Reverse the Pins on the Dual-axis XY Joystick
The original pin configuration on the Dual-axis XY Joystick isn't going to work with our design, we need the pins to stick out of the other side of the board. After some trial and error, I found that the easiest way to do this is as follows.
First bend all the existing pins straight so you can pull the plastic support off of them. As long as they are all linked together it will be very difficult to remove a pin, since all the other ones will be holding it in place.
Use you soldering iron to push on the short end of the pin until it slides into the board as far as it can go.
Turn the board over so you are looking at the long side of the pin. You will need a clamp or clip to hold the board for you since you will need two hands at this point. You will need to apply heat at the base of the pin as you pull on it with pliers. If you think the pin should be moving by now and it isn't, take the heat off, let it cool down, then try again in a minute.These boards are pretty resilient, but just putting heat into it with no limits won't be good for it. When you do it right, the pin will slide free within about 2 or 3 seconds. Repeat until you have all the pins out.
If the holes where the pins were still have solder in them, use a solder sucker or wick to remove the extra solder until you can fit the new pins in matching the picture. Then, solder the new pins in place.
Step 18: Put the Boards in Place
Get the body of the Overkill Control box and put the KeyswitchPlate and the MiniPanel into them as shown.
Pay attention to the position of the PSP joystick and the MiniPanel as you put them in place to make sure you have them oriented correctly. Make sure that you have all three parts of your MiniPanel put together before you insert it.
Each panel will slide into the hole and come to rest on a shelf that holds it firm. Don't be afraid to press firmly, you can't push it too far.
When the MiniPanel is in place, it will be lined up with the top of the control box around it.
When the KeyswitchPlate is in place, it will be about 2 mm below the level of the box around it.
Step 19: Install the Dual-axis XY Joystick
Find the part of the body with the circular hole. This is where the Dual-axis XY Joystick will go. If you look down in the body you will see that there are two slots that fit the corners of the board that the joystick is mounted to. If you aren't sure what you are looking for, look at the JoyPlate, which holds the other end of the board and you will see two similar slots.
Before you insert the Dual-axis XY Joystick, make sure that you put the JoySpacer on the shaft of the joystick and push it down as far as it will go; then put on the joystick cap. Align the joystick module so that the end of the joystick cap pokes out the hole, and the end with the pins goes into the box first. Guide it into the slots that hold the corners and will keep it in place.
Attach female to female jumper wires to each pin and just let the other end be loose for the moment. If you don't have small fingers, you may find it easier to attach the wires first, before installing the joystick.
Step 20: Make the 3-way Ground Connectors
The Teensy 3.6 has a couple of different ground pins but only one analog ground pin. To make things simpler we will treat both he analog and regular ground connectors the same way.
Cut six more sections of 22 gauge solid hook up wire that are about 4 cm or 1.5 inch long and strip about 3 mm of insulation off of one end and 1 cm off the other end of each. You don't need to bend the short end this time, but otherwise these are the same as we have made a few times already.
Tape them together in sets of three to hold the wires in place. Our goal is to solder all three wires together at the end that has 3 mm of wire showing. Bend the wires as shown in picture 2 so that the tips all touch and then solder the three wires together. Once they are firmly soldered, unwrap the electrical tape and straighten the wires, then wrap the electrical tape around the soldered end to keep it from contacting anything it shouldn't touch (see picture 3).
Pictures 4 and 5 show the components we are hooking together. One of these will be used to connect the ground from the two keyplates to the GND pin on the Teensy 3.6 and one will be used to connect the analog ground on the two Joysticks to the Analog GND pin on the Teensy 3.6.
Step 21: Wire It All Up!
The first 3-way ground connector will connect the two joysticks to the Analog GND pin on the Teensy 3.6. Find the jumper wire coming from the Analog GND pin of the Dual-axis XY Joystick and connect it to the 3-way ground connector. Find the jumper wire coming from the Analog GND pin of the PSP 1000 Joystick and connect it to the second wire of the 3-way connector using a female to female jumper wire. Attach a female to female jumper wire to the third wire and connect it to the Analog GND pin on the Teensy 3.6 (picture 3). See the diagrams to help you find the right wires and pins.
Be sure when you are attaching any wires to the MiniPanel or Dual-axis XY Joystick that you go through the holes in the Body to get to the Teensy 3.6, which will live in the larger of the two inner chambers, underneath the KeyPlate. Imagine when we close up the body, if any wires go from the smaller internal chamber to the bigger one and don't go through the holes in the wall between the two, you won't be able to close it up.
Take the second 3-way ground connector and put female to female jumper wires on all three exposed ends.
This will connect to the two keyplates and the GND pin on the Teensy 3.6. Find the exposed end of 22 gauge solid hook up wire that you left on the KeyPlate and attach one to that wire. Find the exposed 22 gauge solid hook up wire that you left on the miniplate, and attach the second there. Attach the third end to the GND pin on the Teensy 3.6 (picture 4).
Your Teensy 3.6 comes with a reference card that labels all the pins You will be using it a lot for the rest of this step.
Our two analog devices need power. Refer to the diagram in picture 1 to find the jumper wire for the Dual-axis XY Joystick that is labeled 3.3v and attach the other end to a pin on the Teensy 3.6 that is labeled as 3.3v. One of these is located right next to the Analog GND. Next find the jumper wire that leads to the 3.3v pin for the PSP 1000 Joystick (see picture 2) and connect the other end to the other 3.3v pin on the Teensy 3.6, which is located next to pin 12.
Next we will hook up all the buttons. Starting with the KeyswitchPlate, starting at the top right and moving right top left, then down a row and continuing in that pattern, hook up the soldered jumper wires starting with pin 0 and continuing through pin 22. At this point it should look like picture 5.
Windows allows for 32 buttons on a joystick without fancy programming magic that I don't have, so we will hook up the uxcell switches next on pins 23 through 28, then the click function for the 5-way switch on pin 29, the click function for the Dual-axis XY Joystick on pin 30, and we will leave pin 31 empty for anyone who wants to customize their box to add one last button/switch.
Follow the diagram to hook up the jumper wires from the rest of the 5 way switch to pins 32, 33, 34, and 35. We get around the problem of being out of joystick buttons by defining this as a "hat switch" in the software.
Follow the diagram for the remaining pins on the two joysticks to connect them to pins 36, 37, 38, and 39.
Everything should be plugged in and ready to go!
Step 22: Closing It Up
Insert the Teensy 3.6 into the TeensyMount as shown in picture 1, then insert the TeensyMount into the MountPlate as shown in picture 2, so that the wires point toward the larger end of the MountPlate. (This two part system lets you open the box without tools after it is all put together. To get it apart, you just press in the TeensyMount, which will let you pull out the MountPlate.)
One trick I found to make it easier to manage all of the little wires going everywhere at this point is to twist the Mount plate one full turn after you put it together and before you mount it into the Body. This helps twist all of the wires together so you don't have to poke them into the Body one by one.
Look at the hole in the back of the Body and line up the Teensy USB port with the hole as you install the MountPlate into the Body. If you put it in backwards you will need to take it apart and turn it around.
Remember when we installed the Dual-axis XY Joystick and it fit into those two slots? The JoyPlate has two slots for the other end of the board that the Dual-axis XY Joystick is mounted on. Line up the slots first, and ease the end of the Dual-axis XY Joystick board into them, then pop the JoyPlate fully into place.
The 3D model of the Body has small supports at the corners to support each of these plates, so as long as you put them in straight, you shouldn't be able to push them in too far. The one exception is the TeensyMount, which is our way back in if we ever need t mess with the wiring later.
Step 23: Adding Keycaps
Turn the Overkill Control box right side up and put the caps back on the uxcell buttons. Then put your keycaps on in whatever order makes sense to you. You can use numbers, letters, symbols, or custom keycaps that you design and 3D print yourself. Depending on what you plan to use it for, you may feel strongly about what each key should show, and it may not matter much, choose keys that make sense to you.
To attach the MultidirectionalCap you will need a little bit of wood glue or white glue. You don't need a lot (see picture 4) but without it the cap is a bit wobbly. To measure how much I need, I dip a wire into the glue to get a drop and then smear it inside the hole in the underside of the MultidirectionalCap. If you put too much glue it will ooze out and the center click function will be glued stuck and not operate, so err on the side of too little glue. If it turns out to be loose later, you can always remove it and add more glue.
Stick the MultidirectionalCap on top of the 5-way switch and give it an hour or so to dry.
Step 24: Final Touches
I have some rubber electrical tape lying around that I found makes excellent non-slip feet. You could use rubber feet you get from a store, foam tape, or whatever you think will work best for you. Technically you don't need anything, but plastic directly on a table can slide around pretty easily so you might want something to help it stay in one place.
Plug your USB cable into the Teensy 3.6 through the hole in the back of the Body, plug the other end into your computer and you are ready to go! Remember to move the PSP 1000 joystick in a big circle to calibrate it if you get any drift so that the software can correct it.
Congratulations on getting through this project!
Step 25: Making Something New!
One of the things I love the most about how the Overkill Control Box turned out is that since I designed it to be 3D printable in parts, it became accidentally modular and customizeable.
If you want to use a different microcontroller, you can design a new mounting plate for it and swap out that part. If you want a different set of switches or keys, you can switch out the KeyswitchPlate for something else that holds toggle switches, or different buttons, or potentiometers. If you want to change the programming, you can write new code and upload it to the Teensy 3.6 (or whatever you replace it with).
Because of this, you could use this for so much more than just video games, you could make a music control DJ tool, or an art program macro and brush styles palette, or whatever you can dream of.
If you make something new out of this, share it with us! I look forward to seeing an instructable that teaches us how to turn the Overkill Control Box into something I never could have dreamed of.
Dream big and share it with the world!